thymin (nucleosin) or 2.6-dioxy-5-methyl pyrimidin hypoxanthin1
or 6-oxypurin, xanthin or 2.6-dioxypurin, adenine or 6
amino-purin, guanine or 2-amino-6-oxypurin, pentoses
(l-xylose), laevulinic acid, ammonia, etc. The nucleic acids
vary with the source of the proteids, there being considerable
differences in chemical composition. In general they are
white, loose powders, slightly soluble in cold water, more
soluble in hot water; they are precipitated by mineral acids,
but dissolve in an excess. They are dextrorotatory, and
the specific rotation is numerically greater than that of
albumin; hence the proteids are, in general, dextrorotatory.
An important nucleo-proteid is haemoglobulin or haemoglobin,
the colouring matter of the red blood corpuscles of vertebrates;
a related substance, haemocyanin, in which the iron of
haemoglobin is replaced by copper, occurs in the blood of
cephalopods and crayfish. Haemoglobin is composed of a
basic albumin and an acid substance haematin; it combines
readily with oxygen, carbon dioxide and carbon monoxide to
form loose compounds (see NUTRITION.) It coagulates at
64 deg. . By a dilute acid haemoglobin is decomposed into
globin, and ``haematin,'' a ferri-pyrrol derivative of the
probable formula C34H34N4FeO5; under certain conditions
the iron-free ``haematoporphyrin'' is obtained. This last
substance may be reduced to mesoporphyrin, C34H38O4N4,
which by further reduction gives haemo-pyrrol, C8H13N,
possibly methyl-propyl-pyrrol or butyl-pyrrol. Other
derivatives are haemin, haemochromogen and the haematinic acids.
``Glyco-proteids'' differ from nucleo-proteids in containing
a carbohydrate radical, which is liberated only by boiling
with mineral acids or alkalies. The mucins and mucoids belong
to this group; they are acid and contain no phosphorus; they
give the albumin colour reactions but are not coagulated by
heat. Mucins occur in most of the slimy fluids of the body; they
vary in composition with their source. Mucoids resemble mucins
in their composition and reactions, but differ, in general, in
their physical properties. They occur in tendons, bones and
cartilage. The ``phospho-glyco-proteids'' resemble the mucins
and mucoids in containing a carbohydrate residue, but differ
in containing phosphorus. Ichthulin (see above) maybe placed
in this group; ``helico-proteid,'' found in the serous gland
of Helix pomatia, the vineyard snail, also belongs here.
Albuminoids is the anatomical name given to albuminous
substances forming the connective tissues. Chemically they
resemble the albumins, being split up by acids or ferments
into albumoses, peptones and amino-acids, forming salts, and
giving the same colour reactions. They are quite insoluble
in water and in salt solutions, and difficultly soluble
in dilute acids and alkalies. Typical albuminoids are
gelatin, keratin, elastin, fibroin, spongin and conchiolin.
``Collagen'' (Gr. kolla, glue, and root gen- of gennaein,
to produce, gignesthai, to become), the ground-substance
of bones and tissues, is decomposed by boiling water or on
warming with acids into substances named gelatin, glutin or
glue. Gelatin forms a white amorphous powder; the commercial
product, however, generally forms glassy plates. The
decomposition products are generally the same as with the
general albumin; it gives the biuret reaction; forms salts
with acids and alkalies, but is essentially acid in nature.
Immersed in cold water gelatin does not dissolve but swells
up; it dissolves readily in hot water, forming, according to
the quantity present, a thick jelly which solidifies to a hard
mass on cooling (the ``glue'' of the wood- worker), or a thin
jelly (used in cookery). Gelatin occurs also in the cornea
and the sclerotic coat of the eye; and in fish scales, the
latter containing 80% of collagen, and 20% of ichthylepidin,
a substance differing from gelatin in giving a well-marked
Millon's reaction. Keratin (Gr. keras, a horn), the chief
constituent of horny material, occurs in hair, nails, hoofs and
feathers. It is quite insoluble in water, dilute acids and
alkalies. Related to this substance are ``neuro-keratin,''
found in the medullary sheath of nerves, and ``gorgonin,''
the matrix of the axial skeleton of the coral Gorgonia
Cavolinii. Elastin occurs either as thick strands or as
membranes; it constitutes the ``elastic tissue'' of the
anatomist. Its insolubility is much the same as keratin.
``Fibroin'' and silk-glue or sericin occur in natural silk
fibres. Fibroin is insoluble in water, acids and alkanes;
silk-glue resembles gelatin in its solubility, but it is less
readily gelatinized. ``Spongin,'' the matrix of bath-sponge, is
insoluble in water and dilute acids, but soluble in concentrated
mineral acids. ``Conchiolin,'' the matrix of shells of the
mollusca, is only slightly soluble in acids. ``Cornein'' forms
the framework of corals. ``Amyloid'' occurs as a pathological
product, and also in the healthy aorta and in old cartilage.
It is an albumin, and not a carbohydrate as was formerly held;
and gives most of the colour reactions of albumins. It forms
shiny, homogeneous masses, quite insoluble in cold water and
in salt solutions, but soluble in alkalies. The albumoids
include, according to Cohnheim, substances which possess
certain properties in common, but differ from the preceding
groups. In general they resemble coagulated albumin, and also the
gelatin-yielding tissues, but they themselves do not yield gelatin.
Colouring matters derived from albumins include the
``melanins'' (Gr. melas, black), substances which differ
very considerably in composition, the sulphur and iron
content being by no means constant; they do not give the
reactions of albumins. The black colouring matter of hair,
the skin of negroes, and of the ink bag of Sepia have been
examined. Melanins obtained from tumours form black,
shiny masses; they are insoluble in water, neutral salt
solutions, dilute acids and in the common organic solvents.
1 6
/N = C\
1 The pyrimidin ring is numbered 2C C5 For the purin
ring, see PURIN. \\N - C//
3 4
ALBUMINURIA (Physiological or Functional), a term indicating
the presence of albumin in the urine. This may depend on
a number of morbid conditions, of which kidney troubles,
acute illnesses and venous congestion are some of the
commoner. But after exclusion of all known pathological
causes, there still remains a large class of cases among
subjects who appear to be in perfect health. This form
has been called functional or physiological albuminuria,
intermittent albuminuria, &c. Its recognition is of extreme
importance, as it must be distinguished from the albuminuria
due to Bright's disease and other troubles. The following
are the main forms that have been described:--(1) Dietetic
Albuminuria. This form affects some people after partaking
of a meal consisting largely of albuminous foods, such as
eggs. In others any extra indulgence in the pleasures of the
table may give rise to it. (2) Cyclic Albuminuria. This name
was first used by the physiologist Pavy, but other observers
have called the same condition ``postural albuminuria.'' It
occurs in people enjoying perfect health, and is characterized
by the presence of albumin in the urine at certain times of the
day. It has been shown to depend entirely on the assumption
of the erect position, and it disappears as a result of
the recumbent position at night. (3) Albuminuria from
exercise. This form affects some people after any unusual
muscular exertion. (4) Prolonged mental strain or worry may
give rise to a transient form of albuminuria. (5) Adolescent
albuminuria is met with in some subjects, especially boys.
The question of the real significance of ``physiological''
albuminuria is one about which there is much difference of
opinion. But its importance and recognition--especially
in questions of life insurance--admits of no question.
ALBUQUERQUE, ALPHONSO D, (in Old Port. AFFONSO
D'ALBOQUERQUE) (1453-1515), surnamed THE GREAT, and
THE PORTUGUESE MARS, was born in 1453 at Alexandria, near
Lisbon. Through his father, Gonzalvo, who held an important
position at court, he was connected by illegitimate descent
with the royal family of Portugal. He was educated at the
court of Alphonso V., and after the death of that monarch
seems to have served for some time in Africa. On his return
he was appointed estribeiro-mor (chief equerry) to John
II. In 1503 he set out on his first expedition to the East,
which was to be the scene of his future triumphs. In company
with his kinsman Francisco he sailed round the Cape of Good
Hope to India, and succeeded in establishing the king of
Cochin securely on his throne, obtaining in return for this
service permission to build a Portuguese fort at Cochin, and
thus laying the foundation of his country's empire in the
East. He returned home in July 1504, and was well received
by King Emmanuel, who entrusted him with the command of a
squadron of five vessels in the fleet of sixteen which sailed
for India in 1506 under Tristan da Cunha. After a series of
successful attacks on the Arab cities on the east coast of
Africa, Albuquerque separated from Da Cunha, and sailed with
his squadron against the island of Ormuz, in the Persian Gulf,
which was then one of the chief centres of commerce in the
East. He arrived on the 25th of September 1507, and soon
obtained possession of the island, though he was unable long
to maintain his position. With his squadron increased by
three vessels, he reached the Malabar coast at the close
of the year 1508, and immediately made known the commission
he had received from the king empowering him to supersede
the governor Francisco de Almeida. The latter, however,
refused to recognize Albuquerque's credentials and cast him
into prison, from which he was only released, after three
months' confinement, on the arrival of the grand-marshal of
Portugal with a large fleet. Almeida having returned home,
Albuquerque speedily showed the energy and determination of his
character. An unsuccessful attack upon Calicut in January
1510, in which the commander- in-chief received a severe
wound, was immediately followed by the investment and capture
of Goa. Albuquerque, finding himself unable to hold the town
on his first occupation, abandoned it in August, to return with
the reinforcements in November, when he obtained undisputed
possession. He next directed his forces against Malacca,
which he subdued after a severe struggle. He remained in
the town nearly a year in order to strengthen the position
of the Portuguese power. In 1512 he sailed for the coast of
Malabar. On the voyage a violent storm arose, Albuquerque's
vessel, the ``Flor de la Mar,'' which carried the treasure
he had amassed in his conquests, was wrecked, and he himself
barely escaped with his life. In September of the same year
he arrived at Goa, where he quickly suppressed a serious revolt
headed by Idalcan, and took such measures for the security
and peace of the town that it became the most flourishing of
the Portuguese settlements in India. Albuquerque had been for
some time under orders from the home government to undertake
an expedition to the Red Sea, in order to secure that channel
of communication exclusively to Portugal. He accordingly
laid siege to Aden in 1513, but was repulsed; and a voyage
into the Red Sea, the first ever made by a European fleet, led
